[FIX] purchase: Error in test

Steps to reproduce the bug:

On a new db, just launch:

./odoo-bin --addons-path=../enterprise,./addons --test-enable -d s11 -i l10n_be,account_accountant,stock,sale_management,purchase

An error occured in test_02_check_mto_chain due to the supplier taxes set on the product.

opw:1878341

closes odoo/odoo#27069

addons/purchase/tests/test_create_picking.py

@@ -119,6 +119,7 @@ class TestCreatePicking(common.TestProductCommon):
             'route_ids': [(4, self.ref('stock.route_warehouse0_mto')), (4, self.ref('purchase.route_warehouse0_buy'))],
             'seller_ids': [(6, 0, [seller.id])],
             'categ_id': self.env.ref('product.product_category_all').id,
+            'supplier_taxes_id': [(6, 0, [])],
         })
 
         customer_move = self.env['stock.move'].create({